A wide and increasing variety of catalysts are currently used in the refining of petroleum derived fuels and lubricants. Of these, a substantial proportion may be characterized as dual-functional in nature, comprising a hydrogenative metal component with a solid acid component. Such acids are defined as possessing Bronsted or Lewis acidity. Such dual-functional catalysts are used in the presence of hydrogen at pressures ranging from atmospheric to 10,000 psig. Examples of processes using these dual-functional catalysts include hydroreforming, hydroisomerization, hydrodewaxing and hydrocracking. In all of these, the acid function is critical to the isomerization, cracking and cyclization reactions that lead to the rearrangement of the carbon skeletons in the organic feed molecules. In fact, deactivation of the acid function by various poisons, even without a concurrent reduction in the effectiveness of the associated metal, is enough to make a catalyst ineffective for such acid catalyzed reactions.